A lifter device used for a seat of an automobile or the like is adapted to adjust a height of a seat cushion to a floor by operating an operating handle, and various types of lifter devices have been developed. In the invention disclosed in JP-A-2016-132423, when an operating handle is operated to be lifted or lowered, the height adjustment is performed by a fixed amount for each operation, and the operation of the operating handle is repeated until reaching a height desired by a seated person.
In the development of a lifter device, it is required to simplify the operation of an operating handle. Specifically, it is desired that when lowering the height of a seat cushion, the height of the seat cushion is continuously lowered only by operating the operating handle once, and when stopping the operation of the operating handle at a height desired by a seated person, the lowering of the seat cushion is stopped at that position.
Accordingly, for example, it is conceivable that a pawl is meshed with a gear rotating in conjunction with the height adjustment of the seat cushion, and when lowering the height of the seat cushion, the meshing state of the pawl to the gear is released, and thus, the seat cushion is lowered by its gravity.
As a problem in the above lifter device, it is assumed that when the meshing between the gear and the pawl is released at the start of the lowering of the seat cushion, abnormal noise is generated from the pawl and the gear at the moment the pawl is separated from the gear.